author_submitExtrinsic - Polkadot

Example code for the author_submitExtrinsic JSON RPC method. Complete guide on how to use author_submitExtrinsic JSON RPC in GetBlock Web3 documentation.

This method submits a signed extrinsic to the node's transaction pool for inclusion in a block and returns its hash. The extrinsic must be constructed and signed by the caller.

Parameters

Parameter	Type	Required	Description
extrinsic	string	Yes	A signed, SCALE-encoded extrinsic, hex-encoded

Request

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{"jsonrpc": "2.0", "method": "author_submitExtrinsic", "params": ["0x4d028400d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d01..."], "id": "getblock.io"}'

JavaScript

example.js

const response = await fetch('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
        jsonrpc: '2.0',
        method: 'author_submitExtrinsic',
        params: ["0x4d028400d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d01..."],
        id: 'getblock.io'
    })
});

const data = await response.json();
console.log(data.result);

Python

example.py

import requests

response = requests.post(
    'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'author_submitExtrinsic',
        'params': ["0x4d028400d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d01..."],
        'id': 'getblock.io'
    }
)

print(response.json()['result'])

Response

{
    "id": "getblock.io",
    "jsonrpc": "2.0",
    "result": "0x8e6c1c623b9d2a2c0e6f6c3b8f0a5d5d1a4b8c9e0f1a2b3c4d5e6f7a8b9c0d1e"
}

Response Parameters

Parameter	Type	Description
id	string	Request identifier matching the request
jsonrpc	string	JSON-RPC protocol version ("2.0")
result	string	The hash of the submitted extrinsic

Use Cases

• Transaction Submission: Broadcast a signed transaction to the network

• Transfers: Submit a balance transfer extrinsic

• Staking Operations: Submit bond, nominate, or payout extrinsics

• Governance: Submit votes and proposals

Error Handling

Error Code	Message	Description
-32602	Invalid params	A parameter is missing or has the wrong type or format
-32601	Method not found	The method is not available on this endpoint
-32603	Internal error	The node failed to process the request

Library Integration

The idiomatic way to call Polkadot RPC is the Polkadot.js API (@polkadot/api), which connects over WebSocket and exposes the method as api.rpc.author.submitExtrinsic.

polkadot-js.js

import { ApiPromise, WsProvider } from '@polkadot/api';

const provider = new WsProvider('wss://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');
const api = await ApiPromise.create({ provider });

const result = await api.rpc.author.submitExtrinsic('0x4d028400d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d01...');
console.log(result.toHuman());